Abstract for: Impact of salt reduction on medical expenditure for hypertension in Japan: national and subnational simulation models

Excessive salt intake affects blood pressure. Thus, monitoring of salt intake is vital in the aging population. In this study, we examined the impact of salt intake reduction on medical expenditure for hypertension in Japan. We developed sub-models of salt intake, population, hypertension, and treatment costs. We built co-flows of foods with high and low salt content and people with high and low salt intakes to calculate the daily salt intake. We built aging chains of 10-year age groups from 40 to 79 years by sex for the population and people with hypertension (PwH). We also calculated the outpatient treatment costs for hypertension. In the base run from 2012 to 2040, a reduction of 46.3% of high-salt foods and 33.1% of people with high salt intake would make a 13.9% reduction of daily salt intake from 10.1 g/day to 8.7 g/day. When salt intake is reduced to 6.9 g/day in 2040, PwH and treatment costs decrease by 2.3% and 2.0% in men and by 8.8% and 8.3% in women, respectively. Our models suggest that reducing salt intake will lead to a decrease in the number of PwH and outpatient treatment costs by 2040. The prefectural models exhibited the simulated changes.